Adjustable scaffold



P. W. MINNIGAN. ADJUSTABLE SCAFFOLD.

APPLICATION FILED lumiao. 1920.

Patented Aug. 2, 1921.-

UNITED STATES PHILIP VJ. MINNIGAN, 0F DAYTON, OHIO.

ADJUSTABLE SCAFFOLD.

Application filed June 30,

To all whom it may concern:

Be it known that I, PHILIP W. MINNI- can, a citizen of the United States, residing at Dayton, in the county of Montgomery and State of Ohio, have invented certain new and useful Improvements in Adjust able scaffolds, of which the following is a specification.

This invention relates to new and useful improvements in adjustable scaffolds. The object of the invention is to provide a device of the above type which is simple in construction, efficient in operation, which is portable and which affords the maximum amount of safety.

Referring to the accompanying drawings, Figure 1 is a front elevation of the invention; Fig. 2 is a side elevation; Fig. 3 is a detail view of the yokes from which the blocks and tackles are suspended; Fig. 4 is a detail view of the struts for holding the upper ends of the ladders away from the building; and Fig. 5 is a section on the line 55 of Fig. 2.

Referring more particularly to the drawings, 1 represents angular supports which, in the present instance, are shown in the form of ladders. The bottom ends of the ladders rest upon the ground -2- while the upper ends are supported against the side of a building 3-. Engaging the sides of the ladders are the bent ends 4- of yokes 5 provided with loops 6. The yokes 5 are mounted at the upper ends of the ladders and the loops -6 rest upon one of the rungs thereof and are adapted to receive the upper ends of blocks and tackles 7. The lower ends of the blocks and tackles are secured at 8 to the upper ends of side boards -9. The lower ends of the side boards are provided with straps 10 which form openings 11 adapted to receive the ends of a platform The platform is supported by the straps 10', the side boards -9, the blocks and tackles 'T, the.yokes 5, and the ladders 1, and the position of the platform, relative to the ground may be adjusted by varying the length of the tackles. The ends of the platform are provided with cleats.l3 which prevent the platform sliding off the straps. The platform is also provided with cleats -14 which, together with rods 15, form trusses for stiffening the platform. The

Specification of Letters Patent.

Patented Aug. 2, 1921.

1920. Serial No. 393,120.

ends of the rods 15 extend through angular reinforcements 16 on the ends of the platform and are provided with suitable nuts. To prevent the platform swinging in a longitudinal direction, the side boards 9 are provided with loops 17 adapted to receive spikes 18- the pointed ends of which being adapted to engage the sides of the building. To prevent the platform swinging in a lateral direction the side boards are provided with a series of pins 19 adapted to receive the aperture ends of struts 20. The other ends of the struts are provided with recesses 21 on their lower sides which are adapted to receive the rungs of the ladders. To hold the upper ends of the ladders away from the building whereby the entire length of the ladders may be used effectively, the said upper ends are provided with angular struts 22- which are attached to the ladders by means of clamps 23. As an element of safety, the scaffold is provided with a hand rail 2l secured to the side boards by loops 25.

Having described my invention, I claim:

1. In an adjustable scaffold, the combination with a pair of ladders, of a yoke for each ladder, each yoke having hook-shaped end portions to engage the outer portions of the ladder rails and having an intermediate loop spaced from said hook-shaped portions and extending to the inner side of said ladder and adapted to rest upon a rung thereof, adjustable suspending devices connected at their upper ends to the loops of the respective yokes, a platform supporting member connected with the lower end of each suspending device, and a platform carried by said supporting members.

2. In an adjustable scaffold, the combination with a pair of ladders, of a yoke for each ladder, each yoke having hook-shaped end portions to engage the outer portions of the ladder rails and having an intermediate loop extending to the inner side of said ladder and adapted to rest upon a rung thereof, adjustable suspending devices connected at their upper ends to the loops of the respective yokes, side boards secured to the lower ends of the respective suspendin devices and having U-shaped straps depen ing therefrom to receive the ends of a platform, and a platform carried by said side boards and having means to hold the same against longitudinal movement relatively thereto.

3. In an adjustable scaffold, the combination with a pair of ladders, of a yoke for each ladder, each yoke having hook-shaped end portions to engage the outer portions of the ladder rails and having an intermediate loop extending to the inner side of said ladder and adapted to rest upon a rung thereof, adjustable suspending devices connected at their upper ends to the loops of the respective hooks, side boards secured to the lower end of the respective suspending devices and having U-shaped straps depending therefrom to receive the ends of a platform, and a platform carried by said side boards and having means to hold the same against longitudinal movement relatively thereto, a strut adjustably connected with each side board and having means for connecting the same with a rung of one of said ladders.

4. In an adjustable scaffold, a one piece yoke adapted to extend transversely to a ladder, having hook-shaped end portions to engage the outer edges of the ladder rails and having an intermediate loop to extend across and rest upon a rung of said ladder,

said loop being adapted to have a platform suspending member connected thereto.

5. An adjustable scaffold, comprising ladders, outwardly spreading struts secured to the upper ends of said ladders and adapted to support them against the Wall of a building, yokes secured to the upper parts of said ladders and having loops formed therein, said'yokes engaging rungs of said ladders and supported thereby, blocks and tackles suspended from said loops on the yokes, side boards suspended from said blocks and tackles, straps secured to said side boards, a platform supported on said straps having cleats preventing individual endwise movement thereof, a hand rail extending from said side boards, struts adapted to be connected to different points of said side boards and to engage different rungs of the ladders to hold the lower errds of said ladders in fixed positions, and pins secured to said plates and adapted to engage said wall, whereby the suspended platform is held stationary relative to the wall and to the ladders.

In testimony whereof I aflix my signature.

PHILIP W. 'MINNIGAN 

